In this article we first give a brief historically based survey of kinematic observations, essentially of rotation curves, of spiral galaxies produced as techniques have advanced and new wavelength ranges have opened up. We then describe the basic inferences from kinematic measurements relevant to galactic structure: the rotational velocity and the velocity dispersion in gas and stars, and how these are made. This is followed by a selection of observations of individual galaxies, picked to illustrate how structural components: bulges, discs, lenses and bars, can be detected and analyzed kinematically as a complement to, or even a substitute for surface photometry. A further section shows how two dimensional kinematic observations of galaxies are even more powerful than one dimensional long--slit optical observations. This is illustrated by Fabry--Pérot mapping of NGC 1530 in Hα, from which we can clearly detect streaming motions in the arms, high velocity flows on either sides of the bar, and inward spiralling gas flow towards the nucleus, and from which we can also relate velocity gradient behaviour with the enhancement or the inhibition of the star formation rate. Finally we explain how continued technical improvement will ensure continued progress in this mature but rewarding field.